Ct Aorta Chest

CT AORTA – CHEST

ANEURYSM/DISSECTION

INDICATIONS: Aneurysm, dissection.“CTA: Aorta, PE. No need to do pre unless looking for acute intramural hematoma or looking at stent grafts.”

PATIENT PREP: NPO for solid food, water only, for 4 hours prior to scan

IV CONTRAST: 100mL Isovue 370 @ 4-5 mL/second

ORAL CONTRAST: None

POSITIONING: Feet First Supine, Arms above head

TOPOGRAMS: AP. Range: Aneurysm: Thoracic inlet to renal arteries, Dissection: Thoracic inlet to aortic bifurcation. 25 mA, 110 kV.

Lateral. Range: Aneurysm: Thoracic inlet to renal arteries, Dissection: Thoracic inlet to aortic bifurcation. 25 mA, 110 kV.

SCAN TYPE: Spiral/Helical

NOTES: ANEURYSM: Scan Range: Thoracic Inlet to Renal Arteries

*FOR HISTORY OF ANEURYSM, USUALLY WITH CONTRAST ONLY, RADIOLOGIST TO PROTOCOL

DISSECTION: Scan Range: Thoracic Inlet to Aortic Bifurcation

*IF DISSECTION PROTOCOL, OBTAIN ORDER FOR CTANGIO CHESTAND AN ORDER FOR CT ANGIO ABDOMEN.

*NONCONTRAST SCAN TO BE PERFORMED FOR DISSECTION PROTOCOL

Send Recon-3D 0.75x0.4mm to Vital Workstation for 3D.

Bill for 3D in Charges section when ending exam: “3D POST PROCESSING CT”

CARE BOLUS triggered scan.

ALARA – Keep radiation dose As Low As Reasonably Achievable.

NONCONTRAST

MONITORING

ScanRange
CARE BOLUS
Monitoring Location / Scan Direction
Scan Type
Number of Scans / Respiration / Threshold / Scan
Delay
Seconds / CARE
DOSE
4D / mAs / kV / Detector Configuration
Slices Per Tube Rotation / Table
Feed / InterScan
Delay
(CycleTime)
Seconds / Scan
Time
Seconds / SFOV
(cm)
Single Slice
Proximal Descending
Aorta / Craniocaudal
Sequential
30 scans / Quiet
Respiration / 150 HU / 15
Seconds / OFF / 40 / 110 / Detectors: 16 x 0.6 mm
Slices Per Tube Rotation: 1 / 0.0 mm / 1.5
Seconds / Full
0.6Sec / 50
cm
Plane / Slice
Thickness / Interval/
Table Feed / Kernal / Window
Width/Level / DFOV
(cm)
RECON – AXIAL SOFT TISSUE / Axial / 9.6 mm / 0.0 mm / B35s
HeartView Medium / Abdomen
300/40 / Small FOV large enough to
Cover region of interest

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ARTERIAL

Scan
Range / ScanDirection
Scan Type / Respiration / Scan
Delay
(Seconds) / CARE
DOSE
4D / Quality
Reference
mAs / kV / Detector Configuration
Slices Per Tube Rotation / Pitch
Table Increment/Speed:
(mm/rotation) / Rotation
Time
(Seconds) / SFOV
(cm)
ANEURYSM: Thoracic Inlet to
Renal Arteries
DISSECTION: Thoracic Inlet to
Aortic Bifurcation / Craniocaudal
Spiral/Helical / Suspended
Inspiration / CARE BOLUS Tracking
(Trigger 150 HU)
Plus 6Second Delay / ON / 90 / 110 / Detectors: 16 x0.6 mm
Slices Per Tube Rotation: 16 / Pitch: 1.3
Table Increment/Speed:
12.48mm/rotation / 0.6
seconds / 50
cm
Plane / Slice
Thickness / Interval / Kernal / Window
Width/Level / DFOV
(cm)
RECON – AXIAL SOFT TISSUE / Axial / 2.0 mm / 2.0 mm / B35s
HeartView Medium / Mediastinum
400/40 / FOV just beyond
patient’s body
RECON – AXIAL LUNG / Axial / 1.0 mm / 1.0 mm / B70s
Sharp / Lung
1200/-600 / FOV just beyond
patient’s body
RECON – CORONAL SOFT TISSUE MPR
Coronals Angled in Plane to Body Part / Coronals Angled in Plane to Body Part
Recon Card 3D Coronal MPR / 2.0 mm / 2.0 mm / B35s
HeartView Medium / Mediastinum
400/40 / FOV just beyond
patient’s body
RECON – SAGITTAL SOFT TISSUE MPR
Sagittals Angled in Plane to Body Part / Sagittals Angled in Plane to Body Part
Recon Card 3D Sagittal MPR / 2.0 mm / 2.0 mm / B35s
HeartView Medium / Mediastinum
400/40 / FOV just beyond
patient’s body
RECON – OBLIQUE SAGITTAL SOFT TISSUE MPR
Oblique Sagittals “Candy Cane” / Oblique Sagittals “Candy Cane”
Recon Card 3D Sagittal/Oblique MPR / 2.0 mm / 2.0 mm / B35s
HeartView Medium / Mediastinum
400/40 / FOV just beyond
patient’s body
RECON – CORONAL MIPS
Coronals Angled in Plane to Body Part / Coronals Angled in Plane to Body Part
Recon Card 3D Coronal MIP Thin / 10.0 mm / 2.0 mm / B35s
HeartView Medium / CT Angio
700/80 / FOV just beyond
patient’s body
RECON – SAGITTAL MIPS
Sagittals Angled in Plane to Body Part / Sagittals Angled in Plane to Body Part
Recon Card 3D Sagittal MIP Thin / 10.0 mm / 2.0 mm / B35s
HeartView Medium / CT Angio
700/80 / FOV just beyond
patient’s body
RECON – 3D ONLY – AXIAL SOFT TISSUE
Send to Vital Workstation for 3D / Axial / 0.75 mm / 0.4 mm / B35s
HeartView Medium / Mediastinum
400/40 / FOV just beyond
patient’s body

*The operator must check the CTDIvol before and after the scan to ensure it is within the allowed dose range. Scans performed outside of the allowed range must be

documented and reviewed by the designated radiologist and/or physicist.

Allowed CTDIvol Dose Ranges:1 mGy – 50 mGy

XR29 Dose Notification Value (CTDIvol):50 mGy

Approximate Values for CTDIvol
Patient Size / Weight (kg) / Weight (lbs) / CTDIvol (mGy)
Small / 50-70 / 110-155 / 4-10
Average / 70-90 / 155-200 / 8-16
Large / 90-120 / 200-265 / 14-22
Reference: AAPM

*The AAPM recommended NEMA XR29 Dose Notification Value for an adult torso is 50 mGy. Dose notification levels less than the AAPM recommended can be set. The maximum CTDIvol should match the dose notification value. Exams with CTDIvol values less than the minimum allowed range should not be performed unless approved by a radiologist.

*IF DISSECTION PROTOCOL: OBTAIN ORDER FOR CT ANGIO CHEST AND AN ORDER FOR CT ANGIO ABDOMEN.

CHARGES:Bill for 3D in Charges section when ending exam: “3D POST PROCESSING CT”

NETWORK:Exam to PACS. Send Recon-3D 0.75x0.4mm to Vital Workstation for 3D

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